jquery.zeroclipboard Demo
HTML
<script src="//rawgit.com/zeroclipboard/jquery.zeroclipboard/master/dist/jquery.zeroclipboard.js"></script>
<div>
<button class="zclip" data-zclip-text="blahblahblah">Copy</button>
</div>
JavaScript
$("body").on("copy", ".zclip", function ( /* ClipboardEvent */ e) {
alert("TEST");
e.clipboardData.clearData();
e.clipboardData.setData("text/plain", $(this).data("zclip-text"));
e.preventDefault();
});